Posted By: Clanton
Rod bearing pic - 12/04/13 09:06 PM
Let me know what you think of the pattern.
Rod bearing pic
Posted By: Crizila
Re: Rod bearing pic - 12/04/13 09:50 PM
My guess is accelerated wear due to poor journal finish. You got others that look like that?
Posted By: Performance Only
Re: Rod bearing pic - 12/04/13 10:15 PM
any chance you could take a picture with better lighting and also a picture of the back of the bearing shells? From what I see it doesn't look good, that's for sure.
Posted By: Clanton
Re: Rod bearing pic - 12/04/13 10:53 PM
The oil had some carbon in it from a rich tune so that may be the finish issue you think you see.Or maybe not but the crank was fresh from Moldex.The back of the bearings show no sign of knock.[like new]
ps:I made about 40 passes on this engine.
ps:I made about 40 passes on this engine.
Posted By: Performance Only
Re: Rod bearing pic - 12/04/13 11:02 PM
A better picture would sure help, even if it had carbon in the oil. It looks like you have an uneven wear pattern that goes all the way to the parting line. Or maybe it's just that the pic is so dark I can't really tell.
Posted By: Clanton
Re: Rod bearing pic - 12/04/13 11:11 PM
I will work on a better pic.I wonder if the pattern is from the rod walking back/forth on the crank..003 clearence,.025 side,15/40 oil,hv pump,80 psi.
Posted By: Crizila
Re: Rod bearing pic - 12/04/13 11:15 PM
Quote:Actually, that's a pretty good pic. Polish the crank, fresh bearings, and party down. Again, do the other bearings look like that?
I will work on a better pic.I wonder if the pattern is from the rod walking back/forth on the crank..003 clearence,.025 side,15/40 oil,hv pump,80 psi.
Posted By: Clanton
Re: Rod bearing pic - 12/04/13 11:30 PM
I only checked 1 rod so far.
Posted By: FastmOp
Re: Rod bearing pic - 12/05/13 02:29 AM
I like to take a ball bearing and a 0-1 micrometer and measure the upper bearing shell. You can measure the crush and tell if it had detonation. Anything more then a couple tenths (.0002) and the tune up is too close to the edge.
If it measures the same as the bottom 1/2 just wipe those off with a wore out green pad and reuse them
I don't really like .003 for clearance. I'd want .002 but I'm no expert.
If it measures the same as the bottom 1/2 just wipe those off with a wore out green pad and reuse them
I don't really like .003 for clearance. I'd want .002 but I'm no expert.
Posted By: Sport440
Re: Rod bearing pic - 12/05/13 02:55 AM
Im no expert, but I dont see him having .003 clearence. It looks to me that somethings not perfectly round. He's got variable clearence IMO.
Id like to see the other rod bearings as well when Mike gets to that point.
Id like to see the other rod bearings as well when Mike gets to that point.
Posted By: Clanton
Re: Rod bearing pic - 12/05/13 04:24 AM
I think the others will be the same.I just happin to have the ball bearings from Steret.[sp]This is not the 1st time I have seen this and I do think the rods are moving making the marks as they are.I will get to the others this wk.
Posted By: jamesc
Re: Rod bearing pic - 12/05/13 04:38 AM
i'd want to know why that cap insert is worn on one side. as for bearing thickness a ball micrometer works nice
Posted By: Clanton
Re: Rod bearing pic - 12/05/13 03:55 PM
Quote:
i'd want to know why that cap insert is worn on one side.
I posted the pic to find that out if I can.I can not measure the crank with the engine in the car very easy but all rods & bearings were measured with a good bore gauge to begin with.
Posted By: Crizila
Re: Rod bearing pic - 12/05/13 04:15 PM
Quote:No 2 ways that the cap/rod/crank journal are not perfectly straight. That's a gimmie. IMO, it is exaggerated by the high bearing wear and coloration of the majority of what's left of the top bearing surface. Most bearing wear charts will show that surface consistency as being caused by poor journal finish - whether the crank was new or not. A better determination can be made when he pulls the other caps off. If they all look similar to this one, I'm stickin with journal finish.Quote:
i'd want to know why that cap insert is worn on one side.
I posted the pic to find that out if I can.I can not measure the crank with the engine in the car very easy but all rods & bearings were measured with a good bore gauge to begin with.
Posted By: MR_P_BODY
Re: Rod bearing pic - 12/05/13 04:27 PM
I wont say anything till I see the others... but the
one edge looks like it doesnt have the radius for
the crank or enough radius for it
one edge looks like it doesnt have the radius for
the crank or enough radius for it
Posted By: BradH
Re: Rod bearing pic - 12/05/13 04:45 PM
Quote:
From what I see it doesn't look good, that's for sure.
And that's the only comment I feel qualified to make on this subject.
I've run lesser powered engines far longer and the bearings from those engines -- while not ideal -- came out with much more consistent wear characteristics.
Posted By: Crizila
Re: Rod bearing pic - 12/05/13 04:53 PM
Quote:I saw that too, but the pic does not show the radius side ( crank fillet side )of the cap or rod, so IMO, inconclusive.
I wont say anything till I see the others... but the
one edge looks like it doesnt have the radius for
the crank or enough radius for it
Posted By: B G Racing
Re: Rod bearing pic - 12/05/13 05:08 PM
Typical of an engine that is constantly being loaded and unloaded by RPM and torque loads and compression pressure in the cylinders.We see this on our blower engine frequently.Sometimes the rods will kick to the crank and also show radius marking. 
Posted By: Clanton
Re: Rod bearing pic - 12/05/13 05:20 PM
Quote:
I wont say anything till I see the others... but the
one edge looks like it doesnt have the radius for
the crank or enough radius for it
The radius on the bearings were turned down to clear the crank.[SLP-8-7135ch .010]
I will try to do 2 more rods on another crank throw.
Posted By: MR_P_BODY
Re: Rod bearing pic - 12/05/13 05:27 PM
Quote:Quote:
I wont say anything till I see the others... but the
one edge looks like it doesnt have the radius for
the crank or enough radius for it
The radius on the bearings were turned down to clear the crank.[SLP-8-7135ch .010]
I will try to do 2 more rods on another crank throw.
Did you verify that they clear the fillet... put a
slight side pressure on the rod and use a feeler gauge
between the crank and rod... I had to cut the bearings
on a couple of my engines and at first I thought I
had it till I checked it with the feeler gauge and
had to go back and add more
Posted By: Clanton
Re: Rod bearing pic - 12/05/13 05:28 PM
Quote:
Typical of an engine that is constantly being loaded and unloaded by RPM and torque loads and compression pressure in the cylinders.We see this on our blower engine frequently.Sometimes the rods will kick to the crank and also show radius marking.
Thank you!I did not think I was the only 1 seeing this.
Posted By: Clanton
Re: Rod bearing pic - 12/05/13 05:36 PM
Quote:Quote:Quote:
I wont say anything till I see the others... but the
one edge looks like it doesnt have the radius for
the crank or enough radius for it
The radius on the bearings were turned down to clear the crank.[SLP-8-7135ch .010]
I will try to do 2 more rods on another crank throw.
Did you verify that they clear the fillet... put a
slight side pressure on the rod and use a feeler gauge
between the crank and rod... I had to cut the bearings
on a couple of my engines and at first I thought I
had it till I checked it with the feeler gauge and
had to go back and add more
What is the feeler gauge for,to space the rod evenly?When I put the engine together I did check to see if the rod was stickey when moved to the radius.
Posted By: Crizila
Re: Rod bearing pic - 12/05/13 05:37 PM
Quote:Hmmm? Unfortunately, didn't save any bearings for comparative pics, but ran Clevite #CB-481-HN's in my blown small block with twice the runs as the OP's and they didn't look like that. All runs were with boost in the 15 - 18 lb range and a few passes pinned a 25 lb boost gauge ( smaller blower pulley). Bearings had enough radius out of the box to fit a factory Scat crank. I
Typical of an engine that is constantly being loaded and unloaded by RPM and torque loads and compression pressure in the cylinders.We see this on our blower engine frequently.Sometimes the rods will kick to the crank and also show radius marking.
to your experience on the subject though. 
Posted By: roadhazard
Re: Rod bearing pic - 12/05/13 06:49 PM
Don't know if this helps anyone out so just throwing it out there. There are multiple images for some of these pictures.
http://catalog.mahleclevite.com/bearing/
http://catalog.mahleclevite.com/bearing/
Posted By: Crizila
Re: Rod bearing pic - 12/05/13 07:23 PM
Quote:Good post
Don't know if this helps anyone out so just throwing it out there. There are multiple images for some of these pictures.
http://catalog.mahleclevite.com/bearing/
. Look at image #1 under "crankshaft flex". Pretty close to the OP's pic. #22 = poor journal surface. Maybe a different bearing ( blower application ?) would help?
Posted By: 80fbody
Re: Rod bearing pic - 12/05/13 07:27 PM
Quote:
Don't know if this helps anyone out so just throwing it out there. There are multiple images for some of these pictures.
http://catalog.mahleclevite.com/bearing/
That's a cool link for sure. Looks kind of like #24.
Posted By: Clanton
Re: Rod bearing pic - 12/05/13 08:31 PM
Here is rod 5 and the other was #1,both having markings on the chamfer side of the cap.
Posted By: B G Racing
Re: Rod bearing pic - 12/05/13 08:48 PM
Typical,don't idle the engine too low. 
Posted By: Clanton
Re: Rod bearing pic - 12/05/13 08:56 PM
Quote:
Typical,don't idle the engine too low.
The idle is 1100+ and 1k in gear.
Posted By: B G Racing
Re: Rod bearing pic - 12/05/13 09:12 PM
Quote:Quote:
Typical,don't idle the engine too low.
The idle is 1100+ and 1k in gear.
You like to hear that rump,rump
Posted By: Clanton
Re: Rod bearing pic - 12/05/13 09:32 PM
Quote:Quote:Quote:
Typical,don't idle the engine too low.
The idle is 1100+ and 1k in gear.
You like to hear that rump,rump
I don't mind at all.
and thank you for your help.